Field of the Invention
The present invention relates to brushes, and more particularly, relates to a hair brush having a structure which renders it particularly useful for blow waving of hair.
In blow waving the brush is used to lift the hair away from the head while a stream of heated air is directed toward the roots of the uplifted strands of hair. This treatment, when applied to an appreciable portion of the hair results in a coiffure with "body," that is, having a thick or full consistency.
In accordance with the concepts of the present invention the blow waving technique establishes multiple desiderata for an effective blow waving brush. Such a brush must be able to withstand the heat of the applied air stream without melting and without softening excessively. This is particularly true of the bristles of the brush which, because of their low individual heat capacity are the portion of the brush most susceptible to thermal effects.
Further, it is desirable that a blow waving brush, (including its bristles) should not present unnecessary interference to the flow of the stream of heated air. Typically, the blow waving operator holds the brush in one hand and with the other hand applies the stream of hot air from a portable blower or hose. The back or block of the brush will be held in a blocking position in the air stream during an appreciable portion of the blow waving application. Because the brush is used to lift the hair while the air stream is directed upon the hair, it is desirable that the brush structure be constructed so as to avoid excessive blocking of the flow of air. This is especially true with respect to the flow of air through the back or block of the brush which would otherwise present a very large effective blocking cross-section to the flow of air through the brush and to the hair.
In order to avoid such blocking, it is desirable that the bristle portion of the brush have a relatively low density or cross-section of bristles as viewed from the back or block of the brush, consistent with satisfactory lifting of the hair.
On the other hand, as a brush is used blow waving, it is applied to the hair in a direction lateral to the brush and it is desirable, therefore, that the distribution of bristles as viewed from the side of the brush have a relatively high cross-sectional density. This can be accomplished by having the bristle distribution substantially uniform and without excessive gaps as viewed from the lateral direction. In this way, the brush will be most efficient for engaging the hair to lift it.
Certain other features are desirable in a brush. It should be easy to clean, and it should minimize scratching of the scalp tissues. Further, the brush should be inexpensive to manufacture and easy to assemble.